Here is the full list of all 40 Desktop Cube-Man achievements.
Reach Level 8
Reach Level 7
Use automatic rifle
Complete Challenge 10
Reach Level 6
Play challenge mode with friends and survive 60s
Reach Level 5
Complete Challenge 9
Reach Level 4
Complete Challenge 8
Complete Challenge 7
Use shotgun
Complete Challenge 6
Open the chat window
Change to new action type
Use handgun
Reach Level 1
Reach Level 2
Reach Level 3
Complete Challenge 3
Complete Challenge 4
Complete Challenge 5
Complete Challenge 2
Complete Challenge 1
Play challenge mode alone and survive 60s
Open the about window
Start challenge mode
Reach Level 9
Reach Level 10
Reach Level 11
Reach Level 12
Reach Level 13
Reach Level 14
Reach Level 15
Complete Challenge 11
Complete Challenge 12
Complete Challenge 13
Complete Challenge 14
Complete Challenge 15
Use gatlin